fix: release to aws s3

[hiento09]

This pull request updates the GitHub Actions workflow for mirroring releases to S3, focusing on simplifying manual triggers, improving reliability, and tightening history retention. The main changes clarify how releases are selected for mirroring, enforce stricter input requirements for manual runs, and reduce the number of retained releases.

Workflow improvements and input handling:

• The workflow_dispatch manual trigger now requires the tag_name input (previously optional), ensuring a release tag must always be specified when running the workflow manually. The release_name input has been removed for simplicity.
• The release resolution logic in the Resolve release step was refactored: for manual runs, only the provided tag_name is accepted (no fallback to latest or by name), and for automatic runs, the release payload is used directly. This makes the workflow more predictable and robust.
• An informational log was added to output the resolved release tag, name, and number of assets for easier debugging.

Retention policy:

• The maximum number of releases retained in releases.json was reduced from 100 to 20, helping to limit storage and improve performance.
• The step name was updated to reflect the configurable retention count ("keep max N entries" instead of "keep max 100 entries").